The European Southern Observatory (ESO) celebrated 50 years in October since the signing of its founding convention. Astronomers from five European countries – Belgium, France, Germany, the Netherlands and Sweden – decided in 2007 to join forces to build a large telescope to survey the southern sky. ESO now operates three observation sites in Chile, including the Very Large Telescope (VLT) at Paranal – an advanced visible-light astronomical observatory. This VLT image of the Thor’s Helmet Nebula was taken on the occasion of the anniversary with the help of Brigitte Bailleul, who won the “Tweet Your Way to the VLT!” competition, during which the public, for the first time, was able to choose what the VLT would observe. The observations were broadcast live over the Internet from the Paranal Observatory. Also known as NGC 2359, the helmet-shaped nebula lies in the constellation Canis Major. It is about 15,000 light-years away from Earth and more than 30 light-years across.