Antoniadi Ridge, over 450 kilometers long, runs along the right side of this image. The ridge transects a large crater (80-km in diameter) and in turn appears to be interrupted by an irregular rimless depression on the floor of the crater. This ridge also crosses smooth plains to the north and intercrater plains to the south of the large crater.

This image (FDS 27325) was acquired during the spacecraft's first encounter with Mercury.

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.