Building telescopes

Imaging the Very Large Telescope (ELT) in action. This artist's rendering shows the Extra Large Telescope at night, in action atop Cerro Armazones in northern Chile. The telescope uses lasers to create artificial stars high in the atmosphere. Credit: ESO/L. Calçada

The Very Large Telescope: The largest telescope mirror in the world will bring the stars closer to Earth

The main mirror of the European Southern Observatory's (ESO) Extremely Large Telescope (ELT), known as M1, will be the largest mirror ever built for a telescope. diameter of more than 39 meters, and will consist of