Dark matter is slowing the spin of the Milky Way's galactic bar

For 30 years, astrophysicists have predicted such a slowdown, but this is the first time it has been measured. The researchers say it gives a new type of insight into the nature of dark matter, which acts like a counterweight slowing the spin.

from Latest Science News -- ScienceDaily https://www.sciencedaily.com/releases/2021/06/210614153956.htm