This impressive volcano at the border of Chile and Bolivia is Licancabur, softly illuminated by the moon in this nightscape view from the Chajnantor Plateau — home of the ALMA radio telescopes. Reaching 5920 meters high, Licancabur contains one of the world’s highest lakes in its summit crater where the conditions simulates the extreme environment of Mars for astrobiological studies on the possibility of life on ancient Mars. An icy forest of penitentes cluster in the foreground. The penitentes are a curious natural phenomenon found in high-altitude regions. They are thin spikes of hardened snow or ice, with sharp edges pointing towards the Sun, reaching heights from a few centimeters up to several meters.