Intergalactic dust is cosmic dust in between galaxies in intergalactic space. Evidence for intergalactic dust has been suggested as early as 1949, and study of it grew throughout the late 20th century. There are large variations in the distribution of intergalactic dust. The dust may affect intergalactic distance measurements, such as to supernova and quasars in other galaxies.
Intergalactic dust can form intergalactic dust clouds, known to exist around some galaxies since the 1960s. By the 1980s, at least four intergalactic dust clouds had been discovered within several megaparsec (Mpc) of the Milky Way galaxy, exemplified by the Okroy cloud.
In February 2014, NASA announced a greatly upgraded database for tracking polycyclic aromatic hydrocarbons (PAHs) in the universe. According to scientists, more than 20% of the carbon in the universe may be associated with PAHs, possible starting materials for the formation of life. PAHs seem to have been formed as early as two billion years after the big bang, are widespread throughout the universe, and are associated with new stars and exoplanets.
- M. E. Bailey; D. A. Williams (1988). Dust in the universe: the proceedings of a conference at the Department of Astronomy, University of Manchester, 14–18 December 1987. CUP Archive. p. 509. ISBN 978-0-521-35580-3.
- Nancy Atkinson - Intergalactic Dust Could Be Messing Up Observations, Calculations (February 26, 2009) - Universe Today
- Hoover, Rachel (February 21, 2014). "Need to Track Organic Nano-Particles Across the Universe? NASA's Got an App for That". NASA. Retrieved February 22, 2014.