POLARIMETRIC STUDY OF THE PLANET MARS
Abstract
Analysis was made of five thousand two hundred measures of the polarized light of Mars, collected during the last nine apparitions of this planet, since 1948. The polarization curves for the bright and the dark areas of the planet are reproduced for each one of the apparitions. The variation of the polarization for the spectral range 1.05 to 0.45 micron is examined. A polarimetric and photometric study of selected samples of minerals indicated the presence, in the bright areas of the planet, of a fine powder of hydrated iron oxide of the limonite type. The seasonal variation of the polarizing properties of the dark areas of Mars follows closely the variation of their darkness at Martian spring; this suggests a seasonal modification of their microscopic contexture. The luminance of the atmosphere of the planet amounts, for a wavelength of 0.6I micron, to Ka (0.6I micron) = 0.0006 stilb/phot; this corresponds to a surface pressure of 30 millibars. The scattering coefficient of the atmosphere at 0.47 micron is Ka(0.47 micron) = 0.00151 stilb/phot. This value shows that the atmosphere of the planet is much too transparent in the blude to mask the markings of the soil.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 30, 1966
- Accession Number
- AD0635928
Entities
People
- Audouin Dollfus
- John H. Focas
Organizations
- Paris Observatory, PSL University