Low-albedo asteroids: analogues with a high polarization at large phase angles

ABSTRACT While remote observations of the linear polarization five low-albedo near-Earth asteroids are available at large phase angles, space missions have collected materials from surface two them and one is already back to Earth. The structure regolith on may be different that encountered larger objects, because their low gravity thermal stress cycling. Dust particles crushed meteorites (i.e. Orgueil Allende) tentatively used as analogues provide a better approach such regoliths. PROGRA2 experiment studies light-scattering properties dust various size distributions under Earth’s either deposited or with clouds lifted by an air-draught, well μ-gravity conditions. Similar maximum in Pmax) values obtained experimentally for dark levitation, showing multiple scattering negligible. increased sensitivity instruments, together imaging techniques, makes it possible study Pmax increasing sizes particles, up mm-sizes above. Our results confirm constituting mm-sized reach 50 per cent good agreement observations. Some also suggested present particles. Also, huge agglomerates made random ballistic deposition considered relevant e.g. pebbles boulders.