[1] Evidence for intergalactic dust has been suggested as early as 1949, and study of it grew throughout the late 20th century.
[1] There are large variations in the distribution of intergalactic dust.
[1] Dust may affect intergalactic distance measurements, such as supernovae and quasars in other galaxies.
[2] Partially due to the dust's absorption and re-emission of visible light, observations of more distant astronomical objects have greater apparent magnitude when conducted in infrared.
[1] By the 1980s, at least four intergalactic dust clouds had been discovered within several megaparsecs of the Milky Way galaxy,[1] exemplified by the Okroy Cloud.