Visual Communication - First Viking pictures

Visual Communication - First Viking pictures VIKING 1 LANDER: First picture, July 20, 1976

This picture is the first image ever returned from the surface of Mars (20 July 1976). It was obtained with a camera in which a nodding mirror scans the instantaneous field of view that is formed by a photodetector along vertical lines, while the upper camera housing rotates in azimuth between successive scans.¹ The picture covers 20° by 57.5° with an angular resolution of 0.04°. It was reconstructed from 6-bit data without digital enhancement. The favorable lighting and viewing geometry is not a coincidence, but is the result of a carefully planned time of landing (sun elevation) and lander orientation (sun azimuth).² The picture was started 25 seconds after touchdown and took 15 seconds to acquire. The alternating bright and dark vertical striations at the left side of the image and the fine particles deposited on the footpad at the right side were caused by a turbulent cloud of dust raised by the lander’s retrorockets.³ (The picture shown here is a highly lossy compressed version for internet use. A picture that is restored on the proper display medium from the original data has a much higher resolution, sharpness and clarity.)

1. F. O. Huck, H. F. McCall, W. R. Patterson and G. R. Taylor. “The Viking Mars Lander Camera,” Space Science Instrumentation 1, 189-241 (1975). Two cameras onboard each one of two landers produced stereo images of the landing sites. Each camera used an array of 12 silicon photodiodes, including 6 bands for color and near-infrared imaging with an angular resolution of 0.12° and four focus steps for broadband imaging with an improved angular resolution of 0.04°.

2. F. O. Huck and S. D. Wall, “Image quality prediction: An aid to the Viking Lander imaging investigation on Mars.” Applied Optics Opt. 15, 1748-1766 (1976).

3. T. A. Mutch, A. B. Binder, F. O. Huck, E. C. Levinthal, S. Liebes, Jr., E. C. Morris, W. R. Patterson, J. B. Pollack, C. Sagan and G. R. Taylor, “The surface of Mars: The view from the Viking 1 Lander.” Science 193, 791-801 (1976).

The first picture was followed immediately by a low-resolution panoramic (60° by 300°) view of the landing site, and on the next day by the color image shown below. VIKING 1 LANDER: First color picture, July 21, 1976

The color of the scene is predominantly moderate yellowish brown with only subtle variations except for some dark grey rocks, and the color of the sky is light yellowish brown.^1,2

1. F. O. Huck, D. J. Jobson, S. K. Park, S. D. Wall, R. E. Arvidson, W. R. Patterson and W. D. Benton, “Spectrophotometric and color estimates of the Viking Lander sites.” J. Geophysical Research 82, 4401-4411 (1977). The color estimates given in this paper were confirmed in 1997 by the Pathfinder lander imaging investigation, as reported by

2. J. N. Maki, J. J. Lorre, P.H. Smith, R. D. Brandt and D. J. Steinwand, “The color of Mars: Spectrophotometric measurements at the Pathfinder landing site.” J. Geophysical Research 104, 8781-8794 (1999).

These initial pictures were followed in the next several months by hundreds of high-resolution panchromatic images and lower resolution color and near-infrared images. The picture shown below is a highly lossy compressed version of part of a high-resolution composite image.

VIKING 1 LANDER: SECTION OF LANDER SITE PANORAMA

Three months later, Viking 2 landed and similarly characterized another site on Mars.¹ In addition to the two cameras, each lander carried instrumentation for biological, chemical and meteorological investigations.

1. T. A. Mutch, et al., “The surface of Mars: The view from the Viking 2 lander.” Science 194, 1277-1283 (1976).

For a detailed anecdotal history of the Viking Lander Imaging Experiment, as told by our team leader, Tim Mutch, par excellence, in his inimitable way, see The Martian Landscape

Web site curator: Glenn Woodell