Cerro Pachón, Star Trails, and a Laser

In this photo taken from the summit of Cerro Pachón, you can see Gemini South's laser guide star system in action. The laser interacts with particles in the Earth's upper atmosphere and allow 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.