Omega Nebula. Coloured infrared image of the Omega Nebula, also known as Messier 17 and NGC 6618. This is a star forming region, characterised by the glow of ionised hydrogen gas which is excited by hot young stars in the centre. The dense star background is in part of the Milky Way, with some stars obscured by long, winding dust clouds. This image was made as part of the Two- Micron All-Sky Survey (2MASS) project.