Rho Ophiuchi nebula. True-colour optical image of nebulosity (IC 4604) surrounding the star Rho Ophiuchi (upper centre) in the constellation Ophiuchus. This is an excellent example of a reflection nebula. These clouds of gas and dust do not have any light of their own, but reflect the light of nearby stars. They typically appear blue as blue light is scattered more than red light. Dark dust clouds can be seen blocking the light of background stars at lower left. The reddish star at lower right is Omicron Scorpii, in Scorpius. This image was produced by digitally combining photographs taken by the UK Schmidt Telescope in blue and red light.