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Infrared photometric behavior and opposition effect of MarsAlthough the instrument wasn't designed for this purpose, data from the imaging spectrometer ISM may be used for studying photometric variations of Mars reflectance, that are related to the surface materials and aerosols physical properties. ISM flew aboard the Phobos-2 spacecraft which orbited Mars from January to March, 1989. About 40,000 spectra were acquired in 128 channels ranging from 0.76 to 3.16 micro-m, with a spatial resolution of 25 km and a signal-to-noise ratio ranging up to 1000. Analysis of the results leads to the following conclusions: width variations of the opposition surge can be related to differences in porosity or grain size distribution on the various domains, with little or no effect from suspended dust. As the biggest effects are observed on dark and bright materials, intermediate behaviors on average-bright regions cannot result from a mixing process, but are more likely to come from either cementation processes or modification of the grain size distribution under the influence of wind, which under Martian conditions preferentially removes the biggest particles. Thus, a surface dust consisting in big bright and small dark grains could explain the observations.
Document ID
Document Type
Conference Paper
Erard, S. (Centre National de la Recherche Scientifique Orsay, France)
Bibring, J-P. (Centre National de la Recherche Scientifique Orsay, France)
Drossart, P. (Observatoire de Paris-Meudon)
Date Acquired
September 6, 2013
Publication Date
January 1, 1992
Publication Information
Publication: Lunar and Planetary Inst., Workshop on the Martian Surface and Atmosphere Through Time
Subject Category
Distribution Limits
Work of the US Gov. Public Use Permitted.
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