A Ghostly Galaxy’s Lack of Dark Matter

Galaxies and dark matter go together like peanut butter and jelly. Rarely is one without the other, but a recently discovered galaxy called NGC 1052-DF2 is nearly entirely lacking in dark matter.
In November 2019, researchers were astonished when they viewed its image captured by the Hubble Space Telescope. Dark matter is an invisible substance that astronomers believe plays an important role in the formation of galaxies and is thought to comprise 85 percent of the universe’s mass.

This discovery not only challenges the ideas of how galaxies form, but also provides evidence that dark matter is real. It shows that dark matter is not always coupled with regular matter in galaxies and that it has its own separate existence.

In addition to lacking dark matter, galaxy NGC 1052-DF2 is an anomaly because you can see straight through it. This is called an ultra-diffuse galaxy because it has an extremely low density. As a result of these findings, a team of researchers are hunting for more dark-matter deficient galaxies to better understand the nature of dark matter and the formation of galaxies.