English: A boulder-strewn field of red rocks stretches across the horizon in this self-portrait of Viking 2 on Mars' Utopian Plain. Fine particles of red dust have settled on spacecraft's surfaces. The same dust is responsible for Mars' salmon-colored sky as the particles hang, suspended in the atmosphere. Color calibration charts for the cameras are mounted at three locations on the spacecraft. The circular structure atop the craft is the high-gain antenna, which is pointed toward Earth. Viking 2 landed Sept. 3,1976, some 4,600 miles from the twin Viking 1 craft, which touched down on July 20.