For over a century, astronomers have marveled at the beauty and complexity of spiral galaxies, which feature arms covered in a multitude of small-scale features known as feathers.

How do spiral galaxies get 'feathers'? All it takes is a little gravity

Source: space
Source Link: https://www.space.com/the-universe/galaxies/how-do-spiral-galaxies-get-feathers-all-it-takes-is-a-little-gravity