Astron. Astrophys. 337, 955-961 (1998)

Seasonal variations of the solar radiation scattered from the putative dust rings of Mars: a possible basis for photometric searches

M.I. Becka and A. Jurewicz

Space Research Centre, Polish Academy of Sciences, ul. Bartycka 18a, 00-716 Warsaw, Poland (e-mail: mib@cbk.waw.pl, aaj@cbk.waw.pl)

Received 9 October 1997 / Accepted 13 May 1998

Abstract

The continuous bombardment of the Martian moonlets Phobos and Deimos by the interplanetary flux of micrometeoroids is believed to produce ejecta, a part of which could be introduced on long-lived circummartian orbits and form tenuous dust rings around the planet. This view is supported by a number of theoretical studies which yield a detailed space structure of the dust rings. There is, however, no direct evidence as to the existence of such rings. We assess the possibility of photometric search after the rings by modelling the field of solar radiance scattered by the putative dust region. The number density distribution of the dust grains around Mars and their size distribution are drawn from the recent theoretical models. The single-scattering albedo of the individual grains is deduced from the reflectance spectra of Phobos, gathered by the spacecraft Phobos 2. A few phenomenological scattering phase functions are taken into account. The largest calculated radiance scattered in the spectral range results to be of the order .

Key words: techniques: photometric planets and satellites: Deimos, Mars, Phobos

Send offprint requests to: M.I. Becka

© European Southern Observatory (ESO) 1998

Online publication: August 27, 1998

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