Types of rocks exposed at the Viking landing sites
Spectral estimates derived from Viking Lander multispectral images have been used to investigate the types of rocks exposed at both landing sites, and to infer whether the rocks are primary igneous rocks or weathering products. These analyses should aid interpretations of spectra to be returned from the Visual and Infrared Mapping Spectrometer on the upcoming Mars Observer Mission. A series of gray surfaces on the Landers were used to check the accuracy of the camera preflight calibrations. Results indicate that the pre-flight calibrations for the three color channels are probably correct for all cameras but camera 2 on Lander 1. The calibration for the infrared channels appears to have changed, although the cause is not known. For this paper, only the color channels were used to derive data for rocks. Rocks at both sites exhibit a variety of reflectance values. For example, reflectance estimates for two rocks in the blue (0.4-0.5 microns), green (0.5-0.6 microns), and red (0.6-0.75 microns) channels are 0.16, 0.23, and 0.33 and 0.12, 0.19, 0.37 at a phase angle of 20 degrees. These values have been compared with laboratory reflectance spectra of analog materials and telescopic spectra of Mars, both convolved to the Lander bandpasses. Lander values for some rocks are similar to earth based observations of martian dark regions and with certain mafic igneous rocks thinly coated with amorphous ferric-oxide rich weathering products. These results are consistent with previous interpretations.
- Research Organization:
- Washington Univ., St. Louis, MO (USA)
- OSTI ID:
- 6610375
- Report Number(s):
- CONF-8510489-
- Journal Information:
- Geol. Soc. Am., Abstr. Programs; (United States), Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Vol. 17; ISSN GAAPB
- Country of Publication:
- United States
- Language:
- English
Similar Records
The Martian surface as imaged, sampled, and analyzed by the Viking landers
Interdisciplinary investigations of comparative planetology. Annual status report, 1 October 1977-30 September 1978. [Cornell Univ. Lab. for Planetary Studies]
Related Subjects
47 OTHER INSTRUMENTATION
58 GEOSCIENCES
580100 -- Geology & Hydrology-- (-1989)
CHEMICAL ANALYSIS
IGNEOUS ROCKS
MAPPING
MARS PLANET
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PLANETS
REMOTE SENSING
ROCKS
SOILS
SPACE VEHICLES
SPECTRAL REFLECTANCE
VEHICLES
VIKING SPACE PROBES