Like the fury of a raging sea, this anniversary image from the NASA/ESA Hubble Space Telescope shows a bubbly ocean of glowing hydrogen, oxygen, and sulphur gas in the extremely massive and luminous molecular nebula Messier 17. This Hubble photograph captures a small region within Messier 17 (M17), a hotbed of star formation. M17, also known as the Omega or Swan Nebula, is located about 5500 light-years away in the Sagittarius constellation. The image, roughly 3 light-years across, was taken on 29-30 May 1999, with Hubble's Wide Field Planetary Camera 2. The colors in the image represent various gases. Red represents sulphur; green, hydrogen; and blue, oxygen.