The Witch Head Nebula (IC 2118) is a reflection nebula in Orion, its distinctive shape sculpted by interstellar dust. The blue color comes from dust scattering the light of Rigel, the bright star just outside the frame.
This image also reveals the faint red glow of hydrogen gas behind the nebula, which is rarely seen in standard views. The contrast between the dust and ionized hydrogen highlights the different components of this region of space.