https://www.vice.com/en_us/article/4agvb9/these-dark-matter-clumps-help-explain-the-material-that-makes-up-most-of-the-universe

One of the biggest unsolved mysteries about our universe is why visible matter—the stuff that makes up planets, stars, and galaxies—is far exceeded by a weird non-luminous substance called dark matter. While scientists don’t know what dark matter is, they have inferred that it exists by its influence on observable phenomena, such as gravitational interactions between galaxies.

Now, a team of astronomers has shed new light on this shadowy substance with the detection of the smallest known dark matter “subhaloes and haloes,” which are terms for the clumpy shape dark matter takes. The discovery was announced this week at the American Astronomical Society meeting in Hawai’i, and is described in a recent study in the Monthly Notices of the Royal Astronomical Society.