Mariner 10 took this picture (FDS 166840) from a distance of 63,400 kilometers (39,300 miles) about an hour after it passed under the South Pole of Mercury. The dark-rimmed crater at upper left is 67 kilometers (42 miles) in diameter. It is surrounded by an extensive ejecta blanket and exhibits a bright ray pattern, which extends into and beyond the larger crater (120 kilometers, 75 miles) to its right and near the picture's center. The dark-rimmed crater is similar to crater Tycho on Earth's moon. The center of this picture is located 33 degrees S. Lat. 158 degrees W. Long. North is to the top.
The Mariner 10 mission, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, 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.