This striking image shows four powerful lasers that form part of the Very Large Telescope in the Atacama Desert, Chile. The lasers make sodium atoms in the atmosphere glow like artificial stars, allowing the telescope to correct for atmospheric distortion of the light from real stars, and so create sharp images. The Very Large Telescope — run by the European Southern Observatory — obtained its first images 25 years ago, in May 1998, and has since been involved in key research including studies of the supermassive black hole at the centre of the Milky Way.