Remote Identification of Soil and Moisture Variation at Gale Crater, Mars
Research School of Astronomy and Astrophysics
The Fenner School of Environment and Society
Mars Society Australia Inc.
Research School of Physics and Engineering, Australian National University
Last modified: June 27, 2011
In a study of Landast MSS multi-wavelength data, Kauth & Thomas (1976) identified that crops and other forms of landcover (e.g. green vegetation, soils, roads) could be distinguished though their spectral reflectance in different channels. In a plot of red versus near-infrared reflectance, bare soils formed a diagonal boundary termed the ‘soil line’ with darker soils lying nearer to the origin (dark in both red and near-ir) and lighter soils having higher values in both bands. In the visible-infrared wavelengths, the reflectance of soils is strongly dependent on moisture content, particle size and texture (percentage of silt, sand and clay), some mineralogy and organic matter content. The distinct spectral response of soils in the red and infrared allows them to be classified remotely. We have applied this technique to red and infrared images of Gale Crater Mars, a potential landing site of the Mars Science Laboratory rover, to observe the spectral variation in soils at the site. We are interested in whether this variation can be explained fully by the range of grain sizes and clay and iron oxide mineralogy, or whether soil moisture is playing an important role.