Elliot C. Morris

The Surface of Mars: The View from the Viking 2 Lander

Viking 2 lander began imaging the surface of Mars at Utopia Planitia on 3 September 1976. The surface is a boulder-strewn reddish desert cut by troughs that probably form a polygonal network. A plateau can be seen to the east of the spacecraft, which for the most probable lander location is approximately the direction of a tongue of ejecta from the crater Mie. Boulders at the lander 2 site are generally more vesicular than those near lander i. Fines at both lander sites appear to be very fine-grained and to be bound in a duricrust. The pinkish color of the sky, similar to that observed at the lander I site, indicates suspension of surface material. However, the atmospheric optical depth is less than that at the lander I site. After dissipation of a cloud of dust stirred during landing, no changes other than those stemming from sampling activities have been detected in the landscape. No signs of large organisms are apparent at either landing site.

The surface of Mars: there view from the viking 1 lander.

The first photographs ever returned from the surface of Mars were obtained by two facsimile cameras aboard the Viking 1 lander, including black-and-white and color, 0.12� and 0.04� resolution, and monoscopic and stereoscopic images. The surface, on the western slopes of Chtyse Planitia, is a boulder-strewn deeply reddish desert, with distant eminences—some of which may be the rims of impact craters—surmounted by a pink sky. Both impact and aeolian processes are evident. After dissipation of a small dust cloud stirred by the landing maneuvers, no subsequent signs of movement were detected on the landscape, and nothing has been observed that is indicative of macroscopic biology at this time and place.

Fine Particles on Mars: Observations with the Viking 1 Lander Cameras

Drifts of fine-grained sediment are present in the vicinity of the Viking 1 lander. Many drifts occur in the lees of large boulders. Morphologic analysis indicates that the last dynamic event was one of general deflation for at least some drifts. Particle cohesion implies that there is a distinct small-particle upturn in the threshold velocity-particle size curve; the apparent absence of the most easily moved particles (150 micrometers in diameter) may be due to their preferential transport to other regions or their preferential collisional destruction. A twilight rescan with lander cameras indicates a substantial amount of red dust with mean radius on the order of 1 micrometer in the atmosphere.

Imaging experiment: The Viking Lander

Abstract The Viking Lander Imaging System will consist of two identical facsimile cameras. Each camera has a high-resolution mode with an instantaneous field of view of 0.04°, and survey and color modes with instantaneous fields of view of 0.12°. Cameras are positioned one meter apart to provide stereoscopic coverage of the near-field. The Imaging Experiment will provide important information about the morphology, composition, and origin of the Martian surface and atmospheric features. In addition, lander pictures will provide supporting information for other experiments in biology, organic chemistry, meteorology, and physical properties.

Viking 1 Lander on the surface of Mars - Revised location

Abstract Late in 1977, the periapsis altitude of the Viking Orbiters was lowered from 1500 to 300 km. The higher resolution of pictures taken at the lower altitude (8 m/pixel) permitted a more accurate determination of the location of the Viking 1 Lander by correlating topographic features seen in the new pictures with the same features in lander pictures. The position of the lander on Viking Orbiter picture 452B11 (NGF Rectilinear) is line 293, sample 1099. This location of the Viking 1 Lander has been used in a revision of the control net of Mars (M.E. Davies, F.Y. Katayama, and J.A. Roth, R2309 NASA, The Rand Corp., Feb. 1978). The new areographic coordinates of the lander are lat 22.483° N and long 47.968° W. The new location is estimated to be accurate to within 50 m.

Surveyor V: Television pictures

Surveyor V landed in a small crater, 8.5 meters wide and 12.5 meters long, which was probably formed by drainage of surficial fragmental debris into a subsurface fissure. The lunar surface debris layer is exposed in the walls of this crater. At depths below about 10 centimeters, the debris appears to be composed mainly of shock-compressed aggregates, ranging from a few millimeters up to 3 centimeters in diameter, set in a matrix of less-coherent finer particles. Rocky chips and fragments larger than a millimeter are dispersed as a subordinate constituent of the debris.

Location of Viking 1 Lander on the surface of Mars

Abstract A location of the Viking 1 Lander on the surface of Mars has been determined by correlating topographic features in the lander pictures with similar features in the Viking orbiter pictures. Radio tracking data narrowed the area of search for correlating orbiter and lander features and an area was found on the orbiter pictures in which there is good agreement with topographic features on the lander pictures. This location, when plotted on the 1:250,000 scale photomosaic of the Yorktown Region of Mars (U.S. Geological Survey, 1977) is at 22.487°N latitude and 48.041°W longitude.

Geology: Physics of fragmental debris

Lunar fragmental debris physics from Surveyor observations, examining size-frequency distribution

In Situ Measurements of the Photometric Properties of an Area on the Lunar Surface

A preliminary determination has been made of the photometric properties of the lunar surface from high–resolution pictures received from the Surveyor I spacecraft. Several target areas were chosen at selected locations around the spacecraft, and photometric measurements were taken with the television camera throughout the lunar day. Surveyor I data agree within ±20% with the terrestrially observed photometric properties. Initial examination of the data indicates no anomalies of the photometric properties of homogeneous areas on scales greater than 6 cm in diameter. Luminance factors were estimated from the observed data and ranged from 7.0% to 7.5% for more than 91% of the area; however, values of 5% to 25% were recorded in some locations. The chromaticity coordinates of the disturbed area near one of the footpads were found to be very close to natural sunlight on a gray paint. A preliminary estimate of the spectral radiance factor of this area is given, using an eigenvector-analysis technique. The spacecraft characteristics, viewing geometry, and ground-recording techniques are included, along with a brief description of errors.

Geology: Fragmental debris

Lunar fragmental debris layer observations from Surveyor project, examining size, shape, texture, structure, etc