Yepun in action

Yepun, Unit Telescope 4 at work on the platform of the Very Large Telescope (VLT). Shining its powerful laser into the Earth's upper atmosphere, astronomers can create artificial stars in a technique called adaptive optics. Adaptive optics allows the corrected optical system to observe finer details of much fainter astronomical objects than is otherwise possible from the ground. The Milky Way can be seen prominently overhead. Captured in this time-lapse during the ESO Ultra High Definition Expedition.