The Monkey (Head) Nebula (designated NGC 2174) is a very bright H II emission nebula located about 6,400 light-years away in the constellation Orion, close to the border with the Gemini constellation. The cloud of dust and gas surrounds the open cluster of young stars called NGC 2175.
As the star cluster heats up the nebula — composed mostly of hydrogen gas — the dust begins to glow. Strong winds and radiation from the massive newly formed stars blow away the nearby material of the dark stellar nurseries in which they formed, creating a shell-like structure.
The dark columns seen on the right side of the nebula are clouds of dust that are silhouetted against the glowing gas of the nebula. These opaque clouds of dust and gas are the birth place of many new stars.
Image Credit: Don Goldman, Ph.D. (Astrodon)