Observational evidence for the scattering properties of interplanetary and cometary dust clouds: an update

Clouds of dust particles and aggregates in the solar system have been known, at least for a decade, to exhibit similar linear polarization phase curves, with a faint negative minimum at a small phase angle, and a wide maximum near 90 degrees. More recently, data inversion techniques and observational campaigns have allowed us to obtain accurate polarization phase curves for interplanetary and cometary dust. The differences pointed out between the characteristics of these curves, together with their wavelength dependence, indicate some differences in the properties of the dust particles. Computational or laboratory tools, which unambiguously link some of the observed trends to these properties, are of major interest to interpret the observational data in terms of origin and evolution of the dust particles. (C) 1999 Elsevier Science Ltd. All rights reserved.