Viking 1 Lander picture of the region of Mars known as Chryse Planitia, the plains of gold, where the spacecraft set down on 20th July 1976. This picture was taken on the 17th February 1977 to document deep-trenching activities. The trench (right of the boom) was dug to obtain samples of Martian soil from a debth of 30 centimetres (12 inches). The boom holds meterological sensors for the measurement of temperature, pressure & wind speed & direction. The large rock covered with the fine red dust of the Martian soil was named Big Joe. The sky above the Martian horizon has an orange/brown cast caused by the suspension of dust particles in the atmosphere.