Dark Nebula
Dark Nebula – A non-luminous interstellar cloud of dust and gas, which is visible because it blocks light from very bright, distant sources.
The arrow points to the dark Horsehead nebula, which is seen in the image due to the more distant, brighter red background nebula.
https://apod.nasa.gov/apod/ap081126.html
Author: Autum Dobbins, UCF Undergraduate 2017
Editor: Patrick Joiner, UCF Interdisciplinary Studies, Class of
2018
Senior Editor: M.M. Montgomery, Ph.D, UCF Physics