interstellar extinction

Interstellar extinction is the dimming of light from stars and other distant objects, especially pronounced in the galactic plane, due the combined effects of interstellar absorption and scattering of light by dust particles. Interstellar extinction increases at shorter (bluer) wavelengths, resulting in interstellar reddening. It is least in the radio and infrared region, which makes these wavelengths suitable for seeing across large distances in the galactic plane and, in particular, for probing the nucleus of the Milky Way.