A laser guide star is a technology used in astronomical adaptive optics to improve the quality of images taken by ground-based telescopes. It involves shining a laser beam into the Earth's atmosphere, creating an artificial "star" that can be used as a reference point for correcting distortions caused by atmospheric turbulence. This allows astronomers to obtain clearer, sharper images of celestial objects by compensating for the blurring effects of the Earth's atmosphere. Laser guide stars have revolutionized ground-based astronomy and have significantly improved the ability of telescopes to capture detailed images of distant galaxies, stars, and other astronomical phenomena.