Big questions call for big telescopes

One of the four unit telescopes at the VLT under a clear night at ESO’s Paranal Observatory. Each of the unit telescopes has a main mirror 8.2 metres in diameter, making them some of the largest single-mirror telescopes in the world. They can be used individually or together and, when combined, are equivalent to a single-mirror telescope of 16 metres, effectively the largest optical telescope in the world. Leading to the publication of an average of more than one peer-reviewed scientific paper per day, the VLT is helping astronomers to answer some of the biggest questions about our Universe.