The ‘Gemini Observatory’ is an astronomy observatory consisting 2 telescopes of 8m, for each hemisphere, Gemini North in Hawaii and Gemini South in Chile regarding Cerro Pachón. Both of these telescopes allow astronomers to cover the entire sky and are among the most powerful working astronomy observatories in the visible and infrared. Each Gemini telescope consists of a high-performance ceramic mirror. These mirrors, like the VLT one, are among the largest mirrors in the world. In Chile, the laboratory of Gemini South is located about sixty kilometres from the telescope itself, in the city of La Serena. It includes the regular base of the astronomers and engineers who develop an important instrument/tool area, including the adaptive optic system ‘Canopus’. This complex system of deformable mirrors allows the real-time correction of atmospheric turbulence. In order to expand the sky covering towards the observed object, it uses the laser's guiding star, i.e. a shining artificial star, closer to observation fields. The Gemini South laser is one of the most powerful in the world. This film shows the routine and the intimacy of a team of scientists and among them Benoît Neichel, a French astronomer specialist of adaptive optics. He takes us through different laboratory sites in La Serena and introduces the current adaptive optic and then the ‘Canopus’ system. Also, he shows us the famous telescope Gemini South with its laser-guiding stars on Cerro Pachón. But beyond the exceptional working environment and fascination that inspires the quest of these researchers, it is the whole question of their condition and their determination which is exposed to us here. From the Grey material, to the Stardust…