A guiding light

These beams of light shooting towards the sky show the laser guide stars of the future Extremely Large Telescope (ELT). Like many other systems on the ELT, the multiple laser guide stars are vital to its operation, helping it adapt to the ever-changing atmospheric conditions above the telescope. This information is sent to the ELT’s M4 mirror which will adjust its shape to compensate for the distortion caused by atmospheric turbulence, allowing astronomers to observe finer details of much fainter astronomical objects than would otherwise be possible from the ground.