Mercury or the Moon?

Caption NASA originale:"After passing Mercury the first time and making a trip around the Sun, Mariner 10 again flew by Mercury on September 21, 1974, at 1:59 PMPDT. This encounter brought the spacecraft in front of Mercury in the Southern Hemisphere.
Much of Mercury looks like the lunar highlands, a scene carved by billions of years of impact craters. This image (FDS 166724)was taken when Mariner 10 was near its closest approach to the planet during the second encounter, from about 50.000 Km. This image is found near the center of the area not imaged during the first encounter".