Intergalactic dust is cosmic dust in between galaxies in intergalactic space. [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. [3]
Intergalactic dust can form intergalactic dust clouds, known since the 1960s to exist around some galaxies. [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. [1]