Observations and laboratory simulations of asteroids by polarization measurements

International audienceWe present polarization observations of C-type asteroids and of (21) Lutetia, one of the targets of the Rosetta mission. The (21) Lutetia phase curves are compared to C-type and M-type asteroid phase curves. In a second part of the work, we use powdered meteorites to compare their polarization at two wavelengths to those observed for different asteroids, e.g., (21) Lutetia and (2867) Steins (the second asteroid observed by Rosetta)