This work examines how thin flakes in for example a cometary atmosphere can be recognized by the way they scatter light. The investigation includes both theoretical modeling and microwave analogue measurements of light scattered by flakes with a size of the order of a few wavelengths and larger. The theoretical modeling adds the transmitted field found using Babinet’s principle and Fresnel’s equations, to an existing model for dielectric edges within the framework of geometrical theory of diffraction. This gives an approximate solution to the scattering by thin 2-dimensional dielectric flakes. The laboratory measurements simulate light scattering by 0.25 μm thick randomly orientated circular silicate flakes of 8 μm diameter.
The modeling of light scattering by flakes is motivated by the desire to recognize flake-like particles in a cometary atmosphere through their light scattering properties. The dynamics of Geminid meteoroids during atmospheric flight and of the Geminid meteor stream in space indicate that flakes may have been produced during cometary activity on asteroid 3200 Phaethon.