This image of the northeastern quadrant of the Caloris basin shows the smooth hills and domes between the inner and outer scarps and the well-developed radial system east of the outer scarp. This image (FDS 193) was taken 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.