Young craters (the largest of which is about 100 kilometers in diameter) superposed on smooth plains. Larger young craters have central peaks, flat floors, terraced walls, radial ejecta deposits, and surrounding fields of secondary craters. Smooth plains have well-developed ridges extending northwest and northeast.
This image (FDS 167) was acquired during the Mariner 10's first encounter with Mercury, is located approximately 60 degrees N, 175 degrees W.
The Mariner 10 mission was managed by the Jet Propulsion Laboratory for NASA's Office of Space Science. It explored Venus in February 1974 on the way to three encounters with Mercury-in March and September 1974 and in March 1975. The spacecraft took more than 7,000 photos of Mercury, Venus, the Earth and the Moon.
Image Credit: NASA/JPL/Northwestern University
Credit: NASA Planetary Photojournal