Abstract
Dust has two major effects on light passing through the Interstellar Medium - Interstellar Extinction and Reddening. Interstellar dust grains are typically a fraction of a micron, approximately the wavelength of blue light and hence light passing through dust is depleted in blue wavelength, causing Interstellar Reddening. Dust Grain Models are mainly based on the analysis of interstellar extinction and polarization curves. Discrete Dipole Approximation (DDA) is the best studied model to compute scattering parameters of the grain.
