The Horsehead Nebula, probably the best known dark/absorption nebula (this means it is so dense that it blocks the visible wavelenghts from behind it). The nebula has a radius of 3.5 light years and is located 1,375 light years from Earth.

https://bit.ly/3y3m5n3 via /r/spaceporn https://bit.ly/3IHDgj5