In this historical photo from the U.S. space agency, sand dunes and large rocks are revealed in this panoramic image of Mars, the first photograph taken by Viking 1's Camera 1 on July 23, 1976. The horizon is approximately 3 kilometers (2 miles) away. The left and right thirds of the picture are the same area that were photographed on July 20 (Sol 0) by camera 2 and provide stereo coverage. The middle third reveals a part of the Martian Surface not seen on the July 20th panorama. The late afternoon sun is high in the sky over the left side of the picture.
The support struts of the S-band high-gain antenna extends to the top of the picture. The American flags are located on the two RTG (Radioisotope Thermoelectric Generator) wind screens. In the middle third of the picture the rocky surface is covered by thick deposits of wind-blown material, forming numerous dunes. At the center of the picture on the horizon are two low hills which may be part of the rim of the distant crater.
Two very large rocks are visible in the middle ground; the nearer one is 3 meters (10 feet) in diameter and is 8 meters (25 feets) from the spacecraft. A cloud layer is visible halfway between the horizon and the top of the picture. The meteorology boom is located right of center. Behind it, the "White Mesa" is visible, which could be seen on the far left side of the Sol 0 Camera 2 panorama. In the nearer ground are numerous rocks about 10cm (4 inches) across, with horse-shoe shaped scour marks on their upwind side and wind tails in their lee. The fine grained material in the front of them contains small pits formed by impact of material kicked out by the lander's descent rocket engines.
Each weekday, SPACE.com looks back at the history of spaceflight through photos (archive).