Star Trails Over Gemini South

This photo shows many stars trailing across the night sky over the course of a long exposure, but you can also see Gemini South's laser guide star system in action. The laser interacts with particles in the Earth's upper atmosphere and allows for real-time corrections of the telescope's optics to compensate for atmospheric turbulence. Gemini South is a part of the International Gemini Observatory, a program of NSF NOIRLab.