With Halloween just weeks away, Nasa has released an eerie image of a nebula that appears to show a witch's head in profile. The formation, officially named IC 2118, has been dubbed the Witch Head Nebula.
The ghostly cloud lies between the constellations Orion and Eridanus, roughly 900 light-years from Earth. Its silhouette suggests a witch with a prominent chin and hooked nose, though the apparition is actually a vast cloud of interstellar gas and dust illuminated by the nearby supergiant star Rigel.
Why the nebula appears blue
The Witch Head is a reflection nebula, shining by reflecting light from a neighbouring star. Its striking blue colour comes from dust grains scattering blue light more efficiently than red, a process similar to the one that makes Earth's daytime sky appear blue.
The nebula is hard to see with the naked eye, but Nasa says keen stargazers can improve their chances by heading to a dark location and using a large-aperture telescope at low magnification.
Star formation and a cosmic broom
An infrared image previously captured by Nasa's Wide-field Infrared Survey Explorer (WISE) revealed clouds within the Witch Head where new stars are forming. The cosmic witch even has a broom, with another formation nicknamed the Witch's Broom located in the Western Veil Nebula in the constellation Cygnus.
