Listening for the Sounds of Dark Matter

Dark matter makes up 85 percent of all the matter in the Universe, yet we cannot see it. But, could it be possible to hear this elusive “something?”

The first clues to the existence of dark matter floating between galaxies came in the 1930’s, from observations of clusters of galaxies by astronomer Fritz Zwicky. These findings were followed up four decades later by groundbreaking astronomer Vera Rubin, when she, along with fellow astronomer Kent Ford, detected the effects of dark matter on the rotational rates of galaxies. Observations conducted at Kitt Peak National Observatory in Arizona provided this first evidence of dark matter within galaxies.

Without the presence of dark matter, galaxies would break apart, and would not form into long-lived clusters. Although we cannot see dark matter (it does not radiate light, heat, or any other form of electromagnetic waves), we can see the effects its mass has on the objects we see in space. Dark matter is now believed to make up 85 percent of all matter in the Universe, nearly seven times as much as every star, planet, and all the gas and dust we see around us.

The presence of dark matter can be seen in this Hubble image of Abell 520, where a collision of two massive galaxy clusters left behind a well of dark matter. Image credit: NASA, ESA, CFHT, CXO, M.J. Jee (University of California, Davis), and A. Mahdavi (San Francisco State University).

One theory suggests dark matter may exist in the form of axion dark matter, and this idea, if correct, could explain many of the mysteries of this elusive “something” pervading space. This axion dark matter would permeate…