[hal-00790178] Laboratory light scattering experiments on meteorites, in preparation for the Rosetta mission

Comparisons between remote observations of small solar system bodies and simulations are of major interest to estimate their properties and prepare space missions. We have developed a programme of laboratory simulations of the light scattering properties of dust, with emphasis on cometary comae and asteroidal surfaces [1]. The purpose is to interpret their linear polarization, which only depends upon the observational conditions (phase angle, wavelength) and the properties of the scattering medium. The PROGRA2 instruments allow us to measure the linear polarization (6deg. to 150deg. phase angle range, 543.5 and 632.8 nm) on layers and levitating dust particles, in the laboratory and during parabolic flight campaigns [2,3]. Measurements on Orgueil and Allegan meteorites samples have shown differences between the properties of clouds or fluffy regoliths and those of deposited layers [4]. Results derived from simulations of cometary dust observations have been confirmed by the analysis of comet Wild 2 samples [5,6]. In the context of the flyby of asteroids Steins and Lutetia in 2008-2010 by the Rosetta spacecraft, we will present results obtained on powders of an aubrite meteorite (possibly a a fragment from Steins or an other E-type asteroid) in a coordinated international programme [7]. We will also present plans for measurements on meteorites that could originate in asteroids similar to Lutetia, as well as on various types of carbonaceous meteorites.



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